Los Angeles and San Francisco have always had an intense sibling rivalry, but two brewers are hoping to improve relations between the Golden State’s greatest metropolises with a beer featuring the flavors of both regions.

When San Francisco’s 21st Amendment Brewery was asked to brew a beer for an “L.A. vs. S.F.” event during San Francisco Beer Week, head brewer David “Zambo” Zamborski decided that collaboration would be more fun than competition, and he reached out to his old friend Jonathan Porter, who had just opened his own brewery, to see about teaming up for a one-off brew.

Porter -- co-owner and brewmaster of Smog City Brewing in Torrance -- had met “Zambo” when they were both brewers at BJ’s Brewhouse in Brea around 2006, and he jumped at the chance to work with him on Smog City’s first collaboration brew.

The result, California Love, is a potent imperial red ale that balances rich and sweet malt character with the pungent flavors of a variety of hops, as well as some specialty ingredients representative of California’s rival regions.

Both brewers are known for their experimentations, and Porter has recently focused on flavoring his hoppy brews with wine grapes. For the collaboration, Pinot Noir must from the Napa Valley was used along with fresh citrus peel from SoCal, and to symbolize the unification of north and south, the whole batch was aged on oak chips. Generously hopped with citra, centennial and amarillo hops, California Love has a pungent and fruity aroma with an assertive malt backbone. The tannic wine grapes dry out the finish of the beer, which is surprisingly quaffable for such a complex and potent (nearly 10% alcohol) brew.

A few kegs of California Love will be sent to the Bay Area for the S.F. Beer Week festivities, and the rest of the 30-barrel (945-gallon) batch will be available at the Smog City tasting room beginning today.